Air heater



Jifl 17, 1923- 1 462339 B. S. HARRISON AIR HEATER Filed'Dep. 28, 1920 2 Sheets-Sheet 1 July 17, 1923- 3 42.339

B. s. HARRISON AIR HEATER Filed Dec. 28, 1920 2 ShwW-Shaet 2 Il'lI inventorof the chamber.

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Patent daily 17, id;

ETE TS hemp T l@' BRISON, 0E BOKLYN, N YORK, ASSIGNOR T0 DRYING YSTS, ENG,

0E CHICAGO, ILLINOIS, A CORPORATION 0E ILLINOIS.

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5:1, 1- e TE.

To all whom it may concern:

Be it known that I, BURT S. HARRISON, a citizen of the United States, and resident of bbrough of Brooklyn, in the county of Kings and State of New York, have invented certain new-and useful. Improvements in Air- Heaters, of which the following is a specification.

This invention relates to improvements in air-heating furnaces designed particularly for the combustion of gaseous or liquid fuels.-

The main object of the invention is to provide a heater which gives the maximum efficiency of heat transfer from the hot gases to the air to be heated, and at the same time overcomes all radiation losses from the combustion chamber by absorbing the radiated heat in the air to be heated.

l accomplish this object by the device illustrated in the accompanying drawings in which- Figure 1 is a vertical longitudinal section of the device.

Figure 2 is a cross .section of the same on the line 22 in Figure 1 and Figure 3 is a cross section on the line 3-3 in Figure 1.

Fig. 4 is a side view of the airheater with the casing and the partitions 4 adjacent the outer wall of the casing shown in section.

The construction here illustrated com prises a horizontally disposed combustion chamber having a burner opening axially located at one end, so that the throw of the flame from the oil burner will be lengthwise The area i of the combustion chamber is suflicient for the complete combustion of the. gases before they leave the combustion chamber. The spent gases in the combustion chamber leave from the end of the horizontal cylinder and then pass in series through a plurality of groups of tubes extending lengthwise of and arranged in a concentric circle around the combustion chamber. The air to be heated enters a surrounding casing and travels in a transverse manner with reference to the tubes and counter-current with reference to the flow of the gases of combustion, that is, the incoming air strikes the tubes first which carry the gases of the lowest temperature or those nearest the stack, and then progressively strikes the hotter tubes and finally passes transversely over the shell of the com- 4. Extending through these partitions from V end to end of the device, I provide a pluralv ity of tubes 5, 5 and 5 which are preferably expanded at their ends into the front and rear partitions.

At the rear of the device, I provide an annularsmoke box 6 which embraces the outlets of the upper tubes 5, and at the front of the device I provide an annular smoke box 7 which embraces the ends of all of the tubes. At the upper part of the smoke box 7 I provide a smoke-uptake 8.

The gases of combustion pass from the combustion chamber 1 into the lower tubes 5 at the rear of the device and are thence drawn through these tubes to the smoke box 7 at the front of the heater and pass thence through the side tubes 5 to the rear smoke box 6, and thence are returned through the upper tubes 5 to the smokebox 7 and are thence discharged through the smoke uptake 8.

Baflle plates 9 and,10 are provided in the smoke boxes 6 and 7 respectively to direct the gases of combustion through the several series of tubes as above described. As shown in Fig. 1, the combustion chamber 1' communicates at the rear of the furnace with a set of tubes 5 The products of combustion are conducted by the tubes 5 in the direction indicated by the arrows in Fig. 4 to the smoke box 7, from which the products of combustion are conducted by the tubes 5 to the smoke box 6, but above thebafies 10, separatingthe inlets of tubes 5 from the outlets of tubes 5 From the smoke box 6 the products of combustion then travel again to the front of the furnace through the tubes 5 into smoke box 7 above the bafiles 9 which divide the smoke box 7 into two compartments, the lower compartment providing communication between the outlets of tubes 5 and the inlets of'tubes 5 The baflles 9 prevent direct Ill.)

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which tubes 5 discharge. I preferably sup-{- port the device on a suitable seat 19 of sad dles 11.

Fresh airfrom is preferably supplied through the port 13 under pressure by means of a fan or other similar device, not shown, 12 between the combustion chamber 1 and the shell or casing 3 which ispreferably di-- vided by an annular partition Y15, and passes thence around this chamber in contact with the tubes 5 5 and 5 containing the heated gases of combustion and thence passes around the end 15 of the partition -15 andis conducted back between thepartition 15 and the combustion chamber 1 in contact with the combustion chamber 1 and passes out by the discharge pipe 14Ifrom which itis supplied to the rooms or chambers to be heated. Aswill be-apparent,the fresh air at the point of introduction to the device and, therefore, at ,itspoint of lowest temperature, is brought into contact with the up ;per tubes containingthe gases of combustion most remote from the source of heat and therefore at their lowesttemperature.

' This fresh air meets, in its passage, tubes the combustion chamber,

containing the gases of. combustion ofprogressively higher temperature so that the maximum heating efliciency of the gases of combustionis attained and the temperature of the heated air may be brought to the temperature of the gases of combustion.

When desired, and where moderate temperature is required, the annular partition 15 maybe omitted and the air circulated about the combustion chamber.

Having thus described my invention what I claim is:

1. In a device of the character described, the combination of a horizontal combustion chamber, a plurality of horizontal ducts for the gases of combustion positioned around a plurality of baflie plates separating the said ducts into sections and adapted to direct the gases of combustion through successive sections of said ducts, a fresh air' duct, a heatingchamber 'brought into contact with heating surfaces a suitable source'of supply to 4 the chamber and an annular dividing plate in said heat-. chamber whereby the fresh air is of progressively higher temperature.

2. In'a'device of the character described, the combination of a horizontal combustion chamber a'heating chamber surrounding the "combustion chamber, a duct for the heated gases of combustion, baflle plates arranged to divide the said duct and means for conducting fresh air around said heating chamber in contact with sections of progressively increasing temperature.

3. In an air heater of the class described, the combination of a horizontal combustion chamber, a plurality of horizontal smoke tubes arranged concentrically around the combustion chamber, a shell surrounding said tubes and combustion chamber, transverse partitions in said shell, and means for conducting fresh air through the spaces in said shell formed bv said partitions.

4. In an air heater of the class described, the combination of a horizontal combustion chamber, a plurality of horizontal smoke tubes arranged concentrically around the combustion chamber, a shell surrounding said tubes and combustion chamber, transverse partitions in said shell, means for conducting fresh air through the spaces in said shell formed by said partitions, an annular partition between said tubes and the wall of the combustion chamber,- and means for effecting a flow of air progressively past the tubes between said annular partition and shell and then between said annular parti-" tubes, and means for directing the air chamber.

through said air BURT HARRISON. 

